1. Field of the Invention
The present invention relates generally to pulse generators and more specifically to a pulse generator which provides sharp pulses independent of rotational velocity.
2. Description of the Prior Art
Magnetic pulse generators of the prior art generally include a permanent magnet having a pick-up coil wound around the magnet. A metallic object or another permanent magnet is rotated relative to the pick-up coil to produce pulses in the coil by intersecting the flux lines of the pick-up coil. This system works well at moderate angular velocities but has a serious drawback at very slow angular velocities. At the lower velocities, the rotating energizing means is in the field of the pick-up coil for a considerable amount of time; thus, a sharp voltage pulse cannot be produced. Therefore, a need exists for a pulse generating system which will provide a sharp pulse in the pick-up coil independent of rotational velocity.
One solution to this problem has been presented by Cathcart in U.S. Pat. No. 2,685,026. By using magnetic shielding devices in the rotating magnetic coil, Cathcart limits the influence of the rotating magnet on the pick-up coil to a finite area and thus produces a sharp pulse.
Other prior art devices have attempted to accomplish the same result by using sophisticated electronics. Also, attempts have been made using a large number of mechanical elements. The use of sophisticated electronics and a large number of mechanical elements increases the cost, as well as reducing the reliability of the equipment. Thus, there exists a need in the prior art to provide an economical and highly reliable pulse generator which provides a sharp voltage pulse irrespective of rotational velocity.